Combined impeller and closure



E. A. MADER COMBINED IMPELLER AND CLOSURE Aug. 21, 1945.

2 Sheets-Sheet 1 Filed June 16, 1945 Snnentor Emil A Mader (Ittorneg E-A. MADER 2,383,004 COMBINED IMPELLER AND CLOSURE Filed June 16, 1945 2Sheets-Sheet 2 Aug. 21, 1945.

Snventor 5722/? A. Ma der A Cittorn g z Patented Aug. 21, 1945 2,383,004COMBINED IMPELLEB AND CLOSURE Emil A. Mader, Detroit, Micln, asslgnor ofonehalf to John Spargo, Detroit; Mich.

Application June 16, 1943, Serial No. 491,264 9 Claims. ('01. 230-114)This invention relates to impellers and particularly impellers fordriving a fluid through openings and serving when idle to automaticallyclose such openings.

An object of the. invention is to provide a bladed rotary impeller, theblades 01. which are yieldably urged to aclosure-forming positionassumed when the impeller is idle, and to adapt the blades to each swingabout two diflerent axes to centrifugally assume an impelllng positionwhen the impeller is driven.

. Another object is to provide a rotary impeller comprising bladesyieldably urged to a closureforming position when the impeller is idleand to mount the blades to swing to impelling positions on pivotalsupports radiating from the impeller axis and to pivot said supports toswing about their inner ends responsive to centrifugal force, arisingwhen the impeller is driven, the swinging of the blades with saidsupports being utilized to pivot them on the supports.

Another object is to provide an impeller hav ing blades individuallypivoted on supports concentrally secured to such hub is a hinge plate ofpolygonal form, pivotally mounting a plurality of equiangularly spacedrods 8 radiating from the hub and adapted to swing transversely to theplane of impeller rotation. Inthe illustrated mounting of said rods,their-inner ends are fixedly inserted in socket members I fixed on hingeleaves 8 whereof the barrels 9 are pinned in the usual manner to barrelsill formed marginally on said hinge plate. The rods 6 pivotally supportsegmental impeller blades II and occupy a bisecting relation to suchblades. Preferably each blade carries bearings l2 and i8 respectively atits inner and outer margins to accommodate the corresponding rod 6, andthe latter have nuts ll threadedon their outer ends to retain the bladeson the rods.

ically converging toward the impeller axis when the impeller is idle,said blades then Jointly forming a closure, the blades and supportsbeing adapted to centrifugally swing substantially into the plane ofimpeller rotation when the impeller is driven, and such swinging beingutilized to pivot the blades on the supports to give them impelllngeflect.

Other objects are to dispose said supports in a substantially bisectingrelation to the blades and to equip the blades with sealing means attheir inner ends.

These and various other objects are attained by the constructionhereinafter described and illustrated in the accompanying drawings,wherein:

Fig. 1 is a view of that side of the impeller from which a fluid is tobe driven, the blades being shown in their closure position.

Fig. 2 is a diametrical sectional view'ot the impeller, taken on thelined-4 of Fig. 1.

Fig. 4 is a diametrical sectional view similar to Fig. 2, but showingthe impelllng position 0! the blades.

The sleeve 3 hasareduced extension lifrom its closed end serving tomount a spider It in spaced coaxial relation with the hub 4. Coiledsprings ll extended to said spider from the socket memhers I urge therods 6 and blades toward said spider, and response of the rods andblades to said springs is limited by stops 18 carried marginally by thespider and projecting in approximate parallelism to the impeller axis.Said stops have their free ends notched as indicated at It! so that suchends, in establishing a limit- ,ing position of the blades, may engagethe latter in a straddling relation to the bearings l2. This assures astable equilibrium for the blades with respect to the pivotal axesestablished by the rods 6. The spider and hub are spaced apart adistance "suited to accommodate the springs I1, and it is preferred toconverge the springs toward the impeller axis 'since this reducesrequisite spacing of the spider and hub. The blades are so shaped andproportioned that. when occupying said limiting position their radialmargins will be lapped slightly and they will jointly assume airusto-conical form. In this form, their inclination to the rotationalplane of the impeller preferably approximates twenty degrees.

The discussed limiting position of the blades 1 is assumed when theimpeller is idle, and when a drive is applied, centrifugal forceovercomes the springs i'l causing the rods 8 to swing about impeller isdriven. Centrifugal force further tends to establish the blades, so faras their curvature permits, in the rotational plane of the rods, butstops are so mounted on the hub as to correspondingly engage the bladesto one side of the pivot rods and thus compel a predetermined pitch ofthe blades to the rotational plane. These stops, as illustrated, areformed by the transversely bent ends of bars 2| which are radiallysecured to the hub by bolts and nuts 22. By inserting one or more shimsor spacers 23 between each bar 2| and the hub, regulation may beeffected of the projecting extent of the stops 20 and thus the impellingpitch 'of the blades may be regulated. Preferably the stops 20 arepositioned slightly outward from the hub, being thus adapted to engageinner portions of the blades, and it is further preferred to bevel theblade-engaging ends of said stops conformingly to the desired pitch ofthe rotating blades.

The function of the impeller, as illustrated, is to induce a flow of airor other fluid through an opening when a drive is applied and to closesuch opening when the impeller is idle. In the construction illustrated,the opening aforementioned is formed by a sheet-metal annulus 24 coaxialwith the impeller, said annulus being set rigidly into a sheet metalplate 25 mounted in any desired manner. The annulus is curvedtransversely to its circumference so that it may have substantially thesame slight clearance from the outer edges of the blades throughout theextent of said edges, when the blades are in their impelling position.When the blades are in their closure-forming position, their outer edgessubstantially form a circle parallel to the medial plane of the annulus24. the width of the latter being preferably adequate to fully surroundthe plates in their impelling position.

To prevent material leakage of air or other fluid between the hub andblades when the latter are idle, it is preferred to provide the inneredges of the blades with sealing flanges 26 projecting from the convexfaces of the blades and proportioned to closely approach the peripheryof the hub when the impeller is at rest. Since one half oieach flange 26must clear the hub when the blades pivot on the rods 6, the radius ofsaid flanges slightly exceeds that of the hub.

It will be noted that the stops 18, in limiting response of the bladesand their pivot rods to the springs l1, predetermine the conicalinclination of the blades and assure that this inclination will be thesame for all of the blades thus adapting them to jointly form aneffective closure. Pressure under which the blades are held against saidstops is adequate to assure against any rattling of the blades, whenidle, due to any ordinary cause such as atmospheric air currents orvibrations induced by machinery.

The general direction of fluid flow induced when the impeller is drivenis indicated by the arrows in Fig. 4, and it will be noted that theconcaved faces of the blades apply the pressure inducing such flow, thisbeing obviously desirable.

In adapting the blades to Jointly form a closure when the impeller is atrest, there is eliminated necessity for pressure-responsive pivotallouvers, now commonly employed to close or open air passages accordingas a fan delivering air to such passages is idle or driven. a

When the described construction is installed in an exterior wall forventilating purposes, the seal established is particularly vital inpreventing rain,

snow, dust, and exterior air from gaining access to a building. In suchan installation, the lapped relation of the blades is also particularlyvital for same reasons.

While the construction has been described as applied to alternatelyimpel air and close an opening through which the air is impelled, it isobvious that the same functions may be exercised with respect to variousother fluids. It is further to be noted that the construction may beinstalled at any desired point within a duct as well as within or upon awall.

The expression plane of impeller rotation" in following claims signifiesany plane transverse to the impeller axis, and the expression radial tothe hub in said claims is used in a materially broader sense thantransverse to the impeller axis."

What I claim is:

1. An impeller comprising a hub, a plurality of blades, supports forsaid blades outwardly extending from the hub. means pivoting saidsupports on the hub to swing toward and from the plane of impellerrotation, means pivoting the blades respectively on the respectivesupports for movement between a position of effective impelling pitchand an idle position of substantially no pitch, means yieldably urgingsaid supports from the plane of impeller rotation, means limitingresponse of the supports to said urging means and establishing for theblades said position of substantially no pitch, the supports and bladesbeing movable, upon driving the impeller, toward the plane of impellerrotation responsive to centrifugal force, and means for pivotallyactuating the blades on the supports responsive to movement toward saidplane to establish an effective pitch of the blades.

2. An impeller comprising a hub, a plurality of blades extendingsubstantially outwardly from the hub, and a provision for mounting theblades on the hub, including means yieldably urging the blades to apredetermined divergency to the plane of impeller rotation, the bladesbeing spaced from the hub in a direction substantially transverse to theplane of impeller rotation responsive to said urging means, a provisionfor substantially closing such space to provide a seal against fluidleakage when the impeller is idle, means affording the blades a pivotalmovement toward and from said plane about axes substantially transverseto that of the hub, and means affording the blades pivotal movementabout axes substantially normal to the first-named axes. the impellerfurther comprising means for inducing and limiting the lastmentionedpivotal movement, responsive to the first-mentioned pivotal movement,the blades being substantially without pitch when the impeller is idle,and centrifugal force being utilized to pivot the blades toward theplane of impeller rotation when the impeller is driven.

3. An impeller comprising a hub, a plurality of blades extendingsubstantially outwardly from the hub, and a provision for mounting theblades on the hub, including means yield'ably urging the blades to apredetermined divergency to the plane of impeller rotation, the bladesbeing spaced from the hub in a direction substantially transverse to theplane of impeller rotation responsive to said urging means, a provisioncarried by the blades for substantially closing such space to provide aseal against fluid leakage when the impeller is idle, means aiiordin theblades a pivotal movement toward and from said plane about axessubstantially transverse to that of the hub, and

means aifording the blades pivotal movement about axes substantiallynormal to the firstnamed axes, the impeller further comprising means forinducing and limiting the'last-mentioned pivotal movement, responsive tothe firstmentioned pivotal movement, the blades being substantiallywithout pitch when the impeller is idle, and centrifugal force beingutilized to pivot the blades toward the plane of impeller rotation whenthe impeller is driven.

4. An impeller comprising a hub, a plurality of blades, supports forsaid blades outwardly extending from the hub, means pivoting saidsupports on the hub to swing toward and from the plane of impellerrotation, means pivoting the blades respectively on the respectivesupports for movement between a position of efiective impelling pitchand an idle position of substantially no pitch, means yieldably urgingsaid supports from the plane of impeller rotation, said urging meansincluding coiled springs and an anchorage memher for such springs spacedfrom the hub, the impeller further comprising stops carried by saidanchorage member limiting response of said sup ports to the urging meansand establishing for the blades said position of substantially no pitch,the supports and blades-being movable, upon driving the impellentowardthe plane of impeller rotation responsive to centrifugal force, andmeans for pivotally actuating the blades on the supports responsive tomovement toward said plane to establish an eflective pitch oi theblades.

5. An impeller comprising a hub, a plurality of blades, supports for theblades outwardly extending from the hub, means pivoting said supports toswing to or from the hub axis about axes substantially transverse to thehub axis, means pivoting the blades respectively on the respectivesupports for movement between a position of effective impelling pitchand a position of substantially no pitch, stop means eflective on thesupports to limit their angular approach to the hub axis, springsrespectively eifective on the respective supports to bias the supportsangularly toward said stop means, arr-anchorage member to which all ofsaid springs are connected, the springs being yieldable to centrifugalforce acting on the blades and supports when the impeller is effectivelydriven, and means for pivotally actuating the blades on the supports andthereby establishing an effective pitch of the blades, responsive to apredetermined centrifugal actuation of the blades.

6. An impeller as set forth in claim 5, said anchorage member beingspaced from the hub along the extended axis of the hub.

7. An impeller comprising a hub, a plurality of blades, supports for theblades outwardly extending from the hub, means pivoting said supports toswing to or from the hub axis about axes substantially transverse to thehub axis, means pivoting the blades respectively 'on the respectivesupports for movement between a position of effective impelling pitchand a position of substantially no pitch, stop means eflective on thesupports to limit their angular approach to the hub axis, meansyieldably biasing the supports abouttheir pivot means toward said stopmeans, such biasing means being yieldable to centrifugal force acting onthe blades and supports when the impeller is effectively driven, andmeans for pivotally actuating the blades on the supports and therebyestablishing an effective pitch of the blades responsive to apredetermined centrifugal actuation of the blades, the hub having atleast one extension outwardly beyond the pivot axes of the supports,limiting outward swinging of the supports about such pivot axes.

8. An impeller comprising a hub, a plurality of blades, supports for theblades outwardly extending from the hub, means pivoting said supports toswing to or from the hub axis about axes substantially transverse to thehub axis, means pivoting the blades respectively on the respectivesupports for movement between a position of effective impellipg pitchand a position of substantially no pitch, stop means efiective on thesupports to limit their angular approach to thehub axis, means yieldablybiasing the supports about their pivot means toward said stop means,such biasing means being-yieldable to centrifugal force acting on theblades and supports when the impeller is effectively driven, and meansfor pivotally actuating the blades on the supports and therebyestablishing an efiective pitch of the blades, responsive to apredetermined centrifugal actuation of the blades, and an annuluswherein the impeller is installed, curved transversely to maintainsubstantially a minimum clearance from the blades in their centrifugallyinduced travel.

9. An impeller comprising a plurality of blades, a hub, a plurality ofrods radiating from the hub and respectively substantially bisecting therespective blades, means pivotallyv mounting the blades on the rods,means pivoting the rods on the hub to turn about axes substantiallytransverse to the hub axis, spring means urging a pivotal movement ofthe rods about the last-mentioned axes, stop members engageable with theblades in a straddling relation to the rods to iirnit such pivotalmovement, said stop members establishing a predetermined conicalinclination of the rods to the hub axis, the blades and rods beingresponsive to centrifugal force, upon rotation of the impeller, toeilect their outward swinging in opposition to said spring means, andstops carried by the hub engaged by the blades in their centrifugalactuation to pivot the blades on the rods and establish a desiredimpelling pitch of the blades.

EMIL A. MADER.

